I have great pressure when the engine is off. I have zero pressure when engine is running. I just picked this truck up and had to replace all of the steel lines due to rust. then I had this problem so I installed a new brake booster and master cylinder. rebleed the lines and still have this lack of pressure when I start the engine. The truck is equiped with Rear ABS.
Sep 19, 2008 at 10:24 PM